When Washington's grand Haft mansion near Embassy Row changed hands in 2006, it was one of the most expensive home sales in the history of the city — and one of its most mysterious.

The 23,000-square-foot, seven-bedroom home — featuring Italian marble floors and a chandelier that had once hung in the Paris Opera House — was sold by discount retail magnate Herbert Haft's widow for $15 million in cash to a company incorporated in Delaware, according to filings. The buyer was never identified.

But interviews and documents reveal for the first time that the mansion is connected to a Russian billionaire who is a key ally of Russian President Vladi­mir Putin and a longtime business associate of Paul Manafort, the recently indicted former chairman of President Trump's campaign.

The Washington Post found that for more than a decade, Russian aluminum magnate Oleg Deripaska has secretly held ties to one of Washington's most prestigious addresses, a property in the heart of the city that is surrounded by powerful political figures and foreign embassies.

In May, White House counselor Kellyanne Conway and her family purchased the home next door for $7.7 million. Vernon Jordan, a close adviser to President Bill Clinton, lives across the street.

Several people familiar with the mansion told The Washington Post that Deripaska was known to them as the property's owner. He directed major renovations and has visited the house several times since 2010, they said. A New York-based company called Gracetown that oversees the property is run by a business associate of Deripaska's, corporate filings show.

The stone edifice,ringed with security cameras,is located on less than an acre behind a high gate on a winding street near Embassy Row. It is less than half a mile from the Naval Observatory, the home of Vice President Pence, and about a mile from the Russian Embassy.

Some of the city's most prominent figures live just on the other side of Rock Creek, including former president Barack Obama and Trump's daughter and son-in-law, White House aides Ivanka Trump and Jared Kushner.

Charles Davidson, executive director of the Kleptocracy Initiative at the Hudson Institute, said the mansion is a striking example of how the world's uber-wealthycan quietly invest in high-end real estate, obscuring their identities through front companies.

"This could be the most spectacular example of it yet — right in our midst," he said.

Lawyers for Deripaska in New York and London and his spokeswoman in Moscow did not respond to requests for comment.

With a net worth recently estimated by Forbes at $5.2 billion, Deripaska, 49, is one of Russia's richest men and considered part of Putin's inner circle. A U.S. diplomatic cable from 2006, published by WikiLeaks, referred to Deripaska as "among the 2-3 oligarchs Putin turns to on a regular basis."

Newsphotographers captured images ofDeripaska conferring with Putin earlier this month during trade meetings in Vietnam that were also attended by President Trump.

Deripaska is known to own a luxury yacht and a private plane and has held property in various cities such as Tokyo and London, according to news reports.

But he has fought to keep secret details of his assets in the United States. In a pending lawsuit in New York related to another Russian-born businessman's claims that Deripaska owes him money, Deripaska has argued that his contact with the United States is too minimal for the state's courts to assert jurisdiction over him. His lawyers successfully argued that hundreds of pages of documents that detail his business and his footprint in this country should be kept under seal, asserting they contain no "information that is of public interest or concern."

However, public portions of the filings show that Deripaska said that he established a trust in the British Virgin Islands that purchased two homes in Manhattan — a $4.5 million townhouse in the West Village in 2006 and a $42.5 million house on the Upper East Side in 2008. Each was purchased by separate companies controlled by the billionaire.

The Haft home was not mentioned in the public court documents. D.C. property records show it was purchased in 2006 by yet another entity: a limited liability company incorporated that year in Delaware called Hestia International, named for the Greek goddess of home and hearth.

The seller was Myrna Ruben Haft, whose marriage to discount retail magnate Herbert Haft two weeks before his 2004 death had sparked headlines and legal action by his children. She had put the home on the market for $20 million.

In an interview, Haft said she did not know the identity of the buyer and had simply been thankful at the time that the sale was conducted quickly and discreetly. "The whole process was done very confidentially," she said.

A man who answered the buzzer at the house's gate last week referred questions about the property to a New York company called Gracetown Inc. A SUV parked in the home's driveway is registered to Gracetown, public records show.

According to New York corporate records, Gracetown's chief ­executive is a Graham Bonham-Carter, a second cousin to the actress Helena Bonham Carter. He lives in London and, according to his LinkedIn profile, works for a company called Terra Services, which British regulatory filings show is owned by Deripaska. He did not respond to requests for comment sent through Facebook and LinkedIn.

People who have seen the mansion since the 2006sale said the interior has been largely gutted and refurbished. D.C. construction permits show that the kitchen was remodeled and some of the house's 11.5 bathrooms were overhauled in the past decade. In addition, the basement was redone, a rear terrace was reconstructed and a new pool and elevator were installed.

The mansion includes a cinema in the basement, a commercial-grade kitchen and a dining room that seats 16.

Deripaska got his start in the aluminum business, thriving in the Wild West days of 1990s post-Soviet capitalism. Since then, he has expanded his business empire into energy, agriculture and aviation.

He also has been a business associate of Manafort's, paying the U.S. political operative to serve as an investment consultant after Manafort began work as a consultant in Ukraine in 2005.

In 2014, Deripaska filed suit in the Cayman Islands, alleging that Manafort had disappeared after taking nearly $19 million intended for investments and failing to account for the funds.

It is not clear how that dispute was settled, but last year, while serving as Trump's campaign chairman, Manafort wrote emails to a Russian former employee indicating he would be willing to conduct "private briefings" about the campaign for Deripaska. Manafort's spokesman has said the emails were an innocuous effort to collect past debts, and Deripaska's spokeswoman has said he never got the message and received no briefings. Deripaska has denied any involvement with the U.S. presidential election.

Deripaska's lawyers said in court documentsthat he has been generally barred from visiting the United States because the U.S. government has refused to extend him visas — meaning he has not been able to visit his Washington home at will.

The Wall Street Journal reported in 2007 that Deripaska's visa struggles stem from suspicions that he had been involved in organized crime, an allegation he has long denied.

Putin has publicly bemoaned Deripaska's visa problems and top Russian officials have routinely raised the matter in private meetings with their U.S. counterparts, according to former U.S. officials familiar with the appeals.

Deripaska did enterthe United States a handful of times using a diplomatic passport, issued to him by the Russian government so he could help assist at summit meetings and other trade missions, according to documents filed in the New York court case.

People traveling on a diplomatic visa are generally barred from conducting personal business, said David Leopold, a former president of the American Immigration Lawyers Association.

Deripaska said in a 2016 court filing that he has had difficulty getting a visa to travel to the United States but used his diplomaticpassport to visit New York 10 times since 2009.

People familiar with the D.C. home said that, on some of those trips, he also visited Washington, staying at the house and reviewing renovations.

It is unclear when Deripaska most recently visited — and whether any of his neighbors know of his tie to the property.

Conway did not respond to requests for comment.

Jordan said he did not know who owned the home.

"I get to look at it when I'm turning onto my street," he said. "Nobody's ever there. It seems like it's abandoned. But they do a good job with the trees and the shrubbery."